Reddit reviews High-Security Mechanical Locks: An Encyclopedic Reference

It depends a little on what you are looking for . . . Some time back, LPL recommended this:

https://www.amazon.com/High-Security-Mechanical-Locks-Encyclopedic-Reference/dp/0750684372

Eventually, you may want to look at picking up High-Security Mechanical Locks: An Encyclopedic Reference.

So I was digging around in the High-Security Mechanical Locks: An Encyclopedic Reference and I found this paragraph. Might help lead you in the right direction.

> In some locks (e.g., American and Laperche), antipicking lower pins are also used. This idea was mooted around 1940 in a patent by Crousore (Fig. 2.22), which called for grooved upper and lower pins cooperating with a channel in the plug. An even earlier method that involved modifications to the lock cylinder was presented in a 1928 patent (US 1,739,964).

You are looking for this book High-Security Mechanical Locks: An Encyclopedic Reference

Are you a mechanical engineer? Id love to compare designs.

Huh, when I copy the text of the comment, I get this: High-Security Mechanical Locks: An Encyclopedic Reference
by Graham W. Pulford

But I just see a comment or it pasted with no text when I view your comment on the official Reddit app. Weird.

High-Security Mechanical Locks: An Encyclopedic Reference
by Graham W. Pulford

Though it's expensive, High-Security Mechanical Locks: An Encyclopedic Reference by Graham Pulford is a fantastic book. It's focused more on the mechanical aspects of higher security locks, most of which are relatively recent, but it does briefly go through the history and development of each lock type, and includes an extremely wide variety of mechanisms.